TM 5-3740-214-14
Table 5-3. Direct and General Support Maintenance Troubleshooting (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE DOES NOT START BUT TURNS OVER (Continued)
b. Check the spark plug visually. Replace it and go to Step 4, if there are:
(1)
Cracks in the insulator.
(2)
Electrodes worn so thin they cannot be regapped.
(3)
Oil fouling, soft wet oil covering the insulator and the plug nose. If there is oil fouling, go to Step 13.
(4)
Build-up of deposits between insulator and the plug shell.
(5)
Broken insulator and/or bent electrode.
NOTE
If the spark plug must be replaced, set the gap at 0.025 inches (0.64 mm). Oil fouling is a sign of
internal engine damage.
Figure 5-26. Spark Plug Gap
c. Check the spark plug gap.
(1)
Reset the gap at 0.025 inches (0.64 mm), if necessary and go to Step 3.
(2)
If the gap is ok, go to Step 3.
d. Check the spark plug for a spark.
(1)
Connect the spark plug wire to the spark plug and set the plug on a grounded part of the engine.
(2)
Turn the ignition switch ON.
(3)
Crank the engine by hand. When the points open and close, a spark will jump between the spark plug
electrodes.
5-23
